Niacin (Vitamin B3)
The original, dirt-cheap NAD⁺ precursor and an essential B vitamin. Raises NAD⁺ like NMN/NR — but the pricier relatives are better tolerated (no 'flush').
How it works
Niacin (vitamin B3) is a direct precursor of NAD+, the central coenzyme for energy production and DNA repair. At high doses it affects blood lipids but often triggers an uncomfortable flush (skin redness). As a NAD+ booster it's cheap but less targeted than NMN or NR.
Dosage
As a vitamin, a few milligrams suffice. High-dose nicotinic acid causes the typical 'flush' (skin reddening); the nicotinamide form does not.
Considerations
As an NAD⁺ booster, niacin reliably raises levels — but the 'longevity' leap is the same unresolved one as with NMN/NR. The once-popular high-dose nicotinic acid for lowering lipids is no longer recommended: large trials (AIM-HIGH, HPS2-THRIVE) showed no cardiovascular benefit but more side effects. Interesting as a cheap NAD source; high dose only under medical guidance.
